Discussions about the Industrial Internet of Things focus on Big Data, the Cloud, and Analytics. They ignore the fact that all of it starts with data.
Discussions about the Industrial Internet of Things cite the need for open standards, often highlighting OPC UA as the standard for bringing information to Big Data, the Cloud, and Analytics. But what about the standard for gathering the data into a controller so OPC UA can take it from there?
The open standard that can gather the data from field devices is PROFINET. And PROFINET is the only 
standard at this level that can integrate data from non-Ethernet field devices as part of that open standard!
These non-Ethernet devices fall into three categories. First, there are strictly mechanical devices like limit switches, lights, and pushbuttons. These connect to IO blocks that are connected to controllers via PROFINET.
Second, there are devices too small to support Ethernet. These might still be intelligent devices containing a microprocessor, but still too small (and too inexpensive) to support Ethernet. IO-Link and AS-interface devices are in this category. Both can be integrated into PROFINET via proxies defined in the PROFINET specification.
Third, there are devices that are installed in an explosive atmosphere, an atmosphere where a spark could cause an explosion. Ethernet cannot be landed on a device in that atmosphere without an expensive explosion-proof housing. But PROFIBUS PA and Foundation Fieldbus can. And they can be integrated into PROFINET via proxies defined in the PROFINET spec.
PROFINET is the only open standard for gathering data that includes the ability to integrate non-Ethernet data as part of the standard!
–Carl Henning